Luke And Leia Might Be Twins - But Thanks To Space Travel, They Wouldn't Be The Same Age

August 25, 2015 | by Jonathan O'Callaghan

Luke and Leia had a bit of a rough time in the Star Wars universe. Twins born during the Great Jedi Purge, they went on to live wholly separate lives, only meeting each other as adults for the first time when faced with defeating the evil Galactic Empire.

A light-hearted piece of research from the University of Leicester has found something rather interesting, though. Based on the distances traveled by the siblings in "Star Wars Episode V: The Empire Strikes Back," they would have had fairly different ages by the end of the movie due to time dilation.

Velocity time dilation is a consequence of Einstein’s theory of relativity. It explains how the faster you travel, the slower time moves for you. So, one twin journeying through space while the other remains stationary would age less. And that’s exactly what happens in the movie.

The paper by students Thomas Griffiths, Duleep Vasudevan, Katie Herlingshaw, and Mark Phillips examined the journeys each sibling took to Cloud City in the movie, where they would ultimately come face to face with Darth Vader. Luke makes the journey from the distant system of Dagobah in his X-Wing, while Leia was in the Anoat system – 25 times closer – and made the journey in the Millennium Falcon.

Despite the Falcon being faster than the X-Wing (0.99999 times the speed of light compared to 0.99995), it is the longer travel time that is key. The time dilation experienced by Leia on her trip was 62.6 days, but for Luke it is 700.8 days (1.92 years). Thus, he will be 1.75 years younger than Leia.

There is a way he could get this back, though: gravitational time dilation. While Leia is in Cloud City, which floats above the Jupiter-like gas giant planet Bespin, time travels slower for her than someone orbiting the planet. But this effect is much less than velocity time dilation. “For Luke to become the same age as Leia he would have to orbit the gas giant for 9.77 million years,” said lead author Griffiths in a statement.

Of course, the research doesn’t take into account the travel time for some of the other movies, but just highlights the effect in this one.

If you think there isn't a massive point to this research, well, you’re probably not entirely wrong. But it’s all in the name of fun, and there is a science aspect, too. The research was conducted as part of the Physics Special Topics module at the University of Leicester, which encourages students to use science to answer some more unusual questions, such as could Noah’s Ark really have been built.

Personally, we think it’s pretty neat. Live long and prosper. Wait, that’s not right...